Composite structural material



April 5, 1932. b. E. Ross ET AL COMPOSITE STRUCTURAL MATERIAL Filed July 28, 1930 Patented Apr; 5, 1 932 UNITEDSTATES PATENT. oFricE DAVID E.'ROS$, FLOYD P. WYMER; AND RICHARD L. HARRISON, OF LA FAYETTE, INDIANA, ASSIGNORS T ROSTONE, INCORPORATED, OF LA FAYETTE, INDIANA, A

CORPORATION OF INDIANA COMPOSITE STRUCTURAL MATERIAL Application filed July 28, 1930. Serial No. 471,268.

This invention is a novel combination structural material having a hard stone-like outer portion or layer and an inner resilient portion or layer, preferably composed of fibrous 5 non-heat conducting and non-sound conducting substances; which material is especially adapted for use in the walls, ceilings and floors of buildings.

v The outer front or stone-like layer is' preferably formed of Rostone, a novel structural material described in the application of Pefi'er, Harrison and Ross, filed February 18th, 1929, Serial No. 341,030; and

' the inner layer may be of vegetable or mineral fibrous material, or mixtures thereof; such for instance as the so-called Celotex or other artificial board which is resilient and a good non-conductor of heat and of sound.

As described in the aforesaid application 20 the essential 'raw materials used in'making Rostone are (a) a mineral substance, such as slate, shale, and certain clays composed wholly or in part of aluminosilicic acid; (b)

and (0) water as an essential reacting'agent. The alkaline earth base and finely ground mineral are mixed with suflicient water to ensure complete reaction and then this raw mixture is indurated by so heating the mass as .will, without destroying the essential water content thereof, transform the mass by reaction into a product possessing high compressive and tensile strength and resistant to attack by ordinary chemical reagents. The resultant product is termed Rostone. We have discovered that a suitably shaped body or layer of the aforesaid raw mixture may be applied to a body or layer of vegetable or mineral fibres or mixtures thereof as aforesaid, and then indurated while so, applied, and that in and by such induration a permanent bond is formed betwen the R0- stone and the fibrous layer and they become inseparable; and the roduct may be handled as an integral unit aving an outer layer or body of hard stone-like appearance capable of taking a high finish, of high compressive strength and resistant to ordinary acid reagents; and an inner layer or body of quite different nature, preferably fibrous lime, magnesia, or other alkaline earthbase,

not and process for which protection is desired.

In the drawings:

Fig. 1 1s a perspective view of a piece of composite structural material embodying our invention.

Fig. 2 is a sectional view thereof.

As shown in the drawings the composite material comprises a layer 1 of Rostone, and a layer 2 of suitable material, preferably fibrous as herein above stated,'such as socalled Celotex or fibre board, and vanous other heat insulating and sound deademng material of this general nature now on the market. These layers or bodies may be of any desired relative thickness and area.

(1) In carrying out our rocess we use as essential raw materials: 81) mineral substances, (slates, shales, and certain clays) from var1ous sources; (6) lime, light-burned? magnesia, or other alkaline earths; (a) water, added to the above, as a necessary ingredient, during mixing.

We preferably use mineral shales, as these occur widely distributed in beds of COIlSid'. erable extent, of homogeneous composition and of the proper degree of purity. We have also employed successfully a mineral known as Halloysite or Indianaite, which occurs in a state of high purity without admixture of free silica or other foreign mineral forms.

We preferably first dry the shale or base material until it contains say one percent or less of free water, and then freely reduce or pulverize same by any suitable means.

(2) The shale is first finely ground or pulverized, and mixed with lime or magnesia m the proportion of substantially one mole of base to one mole of acid.

For example, in the specific case of lime, and, a locally occurring shale commonly termed Fountain County (assuming a mixture of 314 parts of dry components) we would use 56 parts of lime and 258 parts of acid (Al O ,2SiO 2H O) and from 78 to 169 parts of water; in other words, based on 314 parts of dry components, the quantity of water ranges from 20% to 35%, depending on the colloidal condition of the mineral. If at times more water should be added than the amount that will give best results in induration, the excess can be easily removed by evaporation. On the other hand if too little water was added to the mix, more cannot be added after the shapes are formed. Where magnesia is used in place of lime the proportions would be 40 parts magnesia, 258 parts acid and 74 to 160 parts of water. It is obvious that the base requirements of another acid of the series would differ from that given.

(3) Incorporation of the basewith themin eral is effected by well known methods, either in the wet or dry condition. In either case the amount of water necessary in the mass for carr ing out the subsequent reaction is substantially 20-33% (based on the dry weight of. the solid constituents). In the specific case of the shale hereinbefore referred to 20% to 25% is suflicient to permit of easy working. If more highly colloidal clays are used, the water content may be from 25%- to 35%. The mass so made up ma be molded or otherwise formed, either by and or mechanical means, into suitable shapes, as in ordinary ceramic practice.

(4) Hardening or induration of the shaped mass is efl'ected by exposure to the action of heat, while maintaimng within the mass a substantially constant proportion of water. Excess of water above the optimum causes boiling and crumbling, deficiency in water results in a weak and chalky product.

As a heating medium we preferably, but

not necessarily, employ steam; other agencies are effective as hereinbefore' recited. The efi'ect'of steam under pressure in inducing chemical reactions is well known and understood, articularly with reference to silicate techno ogy.

In practice good induration is obtained by the use of steam at substantially atmospheric pressure, and corresponding temperature of substantially 212 degrees F. We however may when treating counter current superheat the steam to any desired temperature, dictated by varying composition in our raw materials, but avoiding high pressures, using only sufficient pressure to secure good circulation.

The indurating reaction for small or medium sized pieces readily takes place in from one to four hours under the conditions set forth.

For pieces of larger size a longer period will be required.

In our process the raw materials for making Rostone are mixed in the manner above described prior to induration; and the fibrous material 2 may be produced or shaped in the form in which it is desired to have it appear in the product. We will herein refer to layer 1 as the stone layer or body and to layer 2 as the fibre layer or body, but it should be .clearly understood that these terms are used in a definitive and not in a limiting sense.

When the raw mixture for making the stone layer is ready for induration it is placed in contact with or 'preferabl superposed upon the fibre layer, by hand or machine, with suflicient pressure to cause interpenetration between the contacting surfaces of the two layers. Then the mass is indurated by subjecting it to low heat, as set forth in the aforesaid application, until the materials in the layer 1 are transformed by chemical reaction into a stone-like product, as above described, and when the induration is completed the Rostone layer will be inseparably connected with the fibre layer and t two may be handled as a unit. '7

The combination product can be'cut with saws or tools and the Rostone layer can be carved or chiseled. In practice the layers could be made'of any desired form or shape. If the product is produced in the form of fiat sheets it can be used and a plied as panels to the walls and ceilings or oors of build.- ings; or the product can be formed or shaped and laid like tile.

The stone layer made of Rostone as described is of high compressive strength and resistant to ordinary chemical reagents. It. can also be made of any desired color by mixing proper pigments with'the raw materials before-induration thereof: If desired inert aggregates may be mixed with the Rostone material before induration thereof.

The invention provides a novel combination structural material combining the advantage of a hard stone-like outer layer or bodyof Rostone with a resilient non-heat and non-sound conducting inner layer or body. Such structural material combines sound deadening and non-heat-conducting and hard ornamental stone-like surface properties in one article of manufacture.

We do not consider our material restricted to use in walls, floors and ceilings of. buildings; as the practical advantages of the invention and numerous useful applications thereof will be readily understood by those skilled in the art.

We claim: 7

1. A structural material comprising a stone-like portion of Rostone and a fibrous body portion inseparably united by and during the induration of the Rostone.

2. A structural material comprising a stone-like portion of Rostone and a fibrous portion inseparably connected by and durproduced by indurating suitable materials and an inner portion or resilient layer of non-heat conducting and non-sound conduct ing material, inseparably united by and during the induration of the materials.

6. A combined structural material comprising an outer layer of synthetic stone and an inner layer of vegetable fibers, inseparably united by and during the induration of the stone layer.

7. A combined structural material comrising an outer layer of Rostone and an inner layer of non-heat conducting and nonsound conducting material, inseparably united by and during the induration of the Rostone.

8. A combination structural material comprising a layer of Rostone and a layer of fibrous material such as Celotex, inseparably connected by and during the induration of the Rostone layer.

hydrated aluminosilicic acid, and water in proper quantity to produce complete reaction; a plying a layer of the mixture to a layer 0 fibrous material; and thereafter heating the mass, While applied to the fibrous layer, by steam until the mass is transformed into a material possessing high compressive and tensile strength and resistant to attack by ordinary chemical reagents and inseparably united to the fibrous layer by and during the transformation of the mass.

12. The herein described rocess of producing an artificial structuralmaterial; consisting in mixing an alkaline earth base, a finely ground mineral material containing hydrated aluminosilicic acid, and water in proper quantity to produce complete reaction; applying a layer of the mixture to a layer of fibrous material; and thereafter heating the mass applied to the fibrous-layer by steam at low pressure, andwithout substantially altering the essential reacting water contact of the mass, until the mass is transformed into a material possessing high compressive and tensile strength and resistant to attack by ordinary chemical reagents and inseparably united to the fibrous layer by and during the transformation of the mass.

DAVID E. ROSS. FLOYD P. WYMER. v RICHARD L. HARRISON.

9. The herein described process of produc- A ing an artificial structural material; consisting in mixing an alkaline earth base, a finely ground mineral material containing hydrated aluminosilicic acid, and water; applyin a mass thereof to a body of fibrous materlal, and heating the mass until it is transformed into a stone-like material inseparably bonded to the fibrous layer by and during the trans- I formation of the mass.

10. The herein described process of producing an artificial structural material; consisting in mixing an alkaline earth base, a

finely ground mineral material containing hydrated aluminosilicic acid, and water in optimum quantity to produce complete reaction; applying a mass thereof'to a body or layer of. fibrous material; and heating the mass until it is transformed into a stone-like 9 material possessing high compressive and tensile strength and inseparably bonded to the fibrous material by and during the transformation of the mass. A

finely ground mineral material containing 1 1. The herein described -rocess of .producing an artificial structur sisting in mixing an alkaline earth base, a

material; con- 

